There is work in anesthetized monkeys (the neural and behavioral signatures of anesthesia are similar to those of coma) demonstrating that high frequency thalamic stimulation is sufficient to restore some markers of wakefulness, even while the monkey is continuously receiving anesthetic. It’s wild.

[0]: https://www.biorxiv.org/content/10.1101/2020.07.07.190132v1

[1]: https://www.sciencedirect.com/science/article/abs/pii/S08966...